PRNG: Switch to /dev/random by default

core/java/src/gnu/crypto/prng/AsyncFortunaStandalone.java

@@ -40,14 +40,13 @@ public class AsyncFortunaStandalone extends FortunaStandalone implements Runnabl
     private AsyncBuffer _currentBuffer;
 
     public AsyncFortunaStandalone(I2PAppContext context) {
-        super(context.getBooleanProperty("prng.useDevRandom") && !SystemVersion.isWindows() && !SystemVersion.isSlow());
+        super(context.getBooleanPropertyDefaultTrue("prng.useDevRandom") && !SystemVersion.isWindows() && !SystemVersion.isSlow());
         _bufferCount = Math.max(context.getProperty("prng.buffers", DEFAULT_BUFFERS), 2);
         _bufferSize = Math.max(context.getProperty("prng.bufferSize", DEFAULT_BUFSIZE), 16*1024);
         _emptyBuffers = new LinkedBlockingQueue<AsyncBuffer>(_bufferCount);
         _fullBuffers = new LinkedBlockingQueue<AsyncBuffer>(_bufferCount);
         _context = context;
-        context.statManager().createRateStat("prng.bufferWaitTime", "Delay for random number buffer (ms)", "Encryption", new long[] { 60*1000, 10*60*1000, 60*60*1000 } );
+        context.statManager().createRateStat("prng.bufferFillTime", "Time to fill random number buffer (ms)", "Encryption", new long[] { 60*60*1000 } );
-        context.statManager().createRateStat("prng.bufferFillTime", "Time to fill random number buffer (ms)", "Encryption", new long[] { 60*1000, 10*60*1000, 60*60*1000 } );
         _log = context.logManager().getLog(AsyncFortunaStandalone.class);
     }
     
@@ -80,12 +79,8 @@ public class AsyncFortunaStandalone extends FortunaStandalone implements Runnabl
     public void seed(byte val[]) {
         Map<String, byte[]> props = Collections.singletonMap(SEED, val);
         init(props);
-        //fillBlock();
     }
   
-    @Override
-    protected void allocBuffer() {}
-    
     private static class AsyncBuffer {
         public final byte[] buffer;
 
@@ -103,7 +98,6 @@ public class AsyncFortunaStandalone extends FortunaStandalone implements Runnabl
             AsyncBuffer old = _currentBuffer;
             if (old != null)
                 _emptyBuffers.offer(old);
-            long before = System.currentTimeMillis();
             AsyncBuffer nextBuffer = null;
 
             while (nextBuffer == null) {
@@ -115,11 +109,6 @@ public class AsyncFortunaStandalone extends FortunaStandalone implements Runnabl
                     continue;
                 }
             }
-            long waited = System.currentTimeMillis()-before;
-            _context.statManager().addRateData("prng.bufferWaitTime", waited, 0);
-            if (waited > 10*1000 && _log.shouldLog(Log.WARN))
-                _log.warn(Thread.currentThread().getName() + ": Took " + waited
-                                   + "ms for a full PRNG buffer to be found");
             _currentBuffer = nextBuffer;
             buffer = nextBuffer.buffer;
         }
@@ -162,26 +151,22 @@ public class AsyncFortunaStandalone extends FortunaStandalone implements Runnabl
     }
     
     private void doFill(byte buf[]) {
-        //long start = System.currentTimeMillis();
+        if (pools != null) {
-        if (pool0Count >= MIN_POOL_SIZE
+            if (pool0Count >= MIN_POOL_SIZE
-            && System.currentTimeMillis() - lastReseed > 100)
+                && System.currentTimeMillis() - lastReseed > 100)
-          {
-            reseedCount++;
-            //byte[] seed = new byte[0];
-            for (int i = 0; i < NUM_POOLS; i++)
               {
-                if (reseedCount % (1 << i) == 0) {
+                reseedCount++;
-                  generator.addRandomBytes(pools[i].digest());
+                //byte[] seed = new byte[0];
-                }
+                for (int i = 0; i < NUM_POOLS; i++)
+                  {
+                    if (reseedCount % (1 << i) == 0) {
+                      generator.addRandomBytes(pools[i].digest());
+                    }
+                  }
+                lastReseed = System.currentTimeMillis();
               }
-            lastReseed = System.currentTimeMillis();
+        }  // else we're using DevRandom
-          }
         generator.nextBytes(buf);
-        //long now = System.currentTimeMillis();
-        //long diff = now-lastRefill;
-        //lastRefill = now;
-        //long refillTime = now-start;
-        //System.out.println("Refilling " + (++refillCount) + " after " + diff + " for the PRNG took " + refillTime);
     }
     
 /*****

core/java/src/gnu/crypto/prng/DevRandom.java

@@ -18,10 +18,17 @@ class DevRandom implements IRandomStandalone {
     private static final String F = "/dev/random";
     private final File file = new File(F);
 
+    /**
+     *  @since 0.9.66
+     */
+    public static boolean isSupported() {
+        return (new File(F)).canRead();
+    }
+
     public String name() { return F; }
 
     public void init(Map<String, byte[]> attributes) {
-        if (!file.canRead())
+        if (!isSupported())
             throw new IllegalStateException("Cannot open " + F);
     }
 
@@ -29,9 +36,6 @@ class DevRandom implements IRandomStandalone {
         throw new IllegalStateException("unsupported");
     }
 
-    /**
-     *  @since 0.9.58 added to interface
-     */
     public void nextBytes(byte[] out) throws IllegalStateException {
         nextBytes(out, 0, out.length);
     }

core/java/src/gnu/crypto/prng/FortunaStandalone.java

@@ -48,7 +48,6 @@ import java.io.Serializable;
 import java.security.InvalidKeyException;
 import java.security.MessageDigest;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.Map;
 
 import net.i2p.crypto.CryptixAESKeyCache;
@@ -104,6 +103,7 @@ public class FortunaStandalone extends BasePRNGStandalone implements Serializabl
   static final int NUM_POOLS = 32;
   static final int MIN_POOL_SIZE = 64;
   protected final IRandomStandalone generator;
+  /** null if using DevRandom */
   protected final MessageDigest[] pools;
   protected long lastReseed;
   private int pool;
@@ -121,23 +121,22 @@ public class FortunaStandalone extends BasePRNGStandalone implements Serializabl
    */
   public FortunaStandalone(boolean useDevRandom) {
     super("Fortuna i2p");
+    if (useDevRandom && !DevRandom.isSupported())
+        useDevRandom = false;
     generator = useDevRandom ? new DevRandom() : new Generator();
-    pools = new MessageDigest[NUM_POOLS];
+    if (useDevRandom) {
-    for (int i = 0; i < NUM_POOLS; i++)
+        pools = null;
-      pools[i] = SHA256Generator.getDigestInstance();
+    } else {
-    allocBuffer();
+        pools = new MessageDigest[NUM_POOLS];
-  }
+        for (int i = 0; i < NUM_POOLS; i++) {
-
+            pools[i] = SHA256Generator.getDigestInstance();
-  /** Unused, see AsyncFortunaStandalone */
+        }
-  protected void allocBuffer() {
+    }
-    buffer = new byte[64*1024];
   }
 
   /** Unused, see AsyncFortunaStandalone */
   public void seed(byte val[]) {
-      Map<String, byte[]> props = Collections.singletonMap(SEED, val);
+      throw new UnsupportedOperationException("use override");
-      init(props);
-      fillBlock();
   }
   
   public void setup(Map<String, byte[]> attributes)
@@ -152,31 +151,14 @@ public class FortunaStandalone extends BasePRNGStandalone implements Serializabl
   /** Unused, see AsyncFortunaStandalone */
   public void fillBlock()
   {
-    //long start = System.currentTimeMillis();
+      throw new UnsupportedOperationException("use override");
-    if (pool0Count >= MIN_POOL_SIZE
-        && System.currentTimeMillis() - lastReseed > 100)
-      {
-        reseedCount++;
-        //byte[] seed = new byte[0];
-        for (int i = 0; i < NUM_POOLS; i++)
-          {
-            if (reseedCount % (1 << i) == 0) {
-              generator.addRandomBytes(pools[i].digest());
-            }
-          }
-        lastReseed = System.currentTimeMillis();
-      }
-    generator.nextBytes(buffer);
-    //long now = System.currentTimeMillis();
-    //long diff = now-lastRefill;
-    //lastRefill = now;
-    //long refillTime = now-start;
-    //System.out.println("Refilling " + (++refillCount) + " after " + diff + " for the PRNG took " + refillTime);
   }
 
     @Override
   public void addRandomByte(byte b)
   {
+    if (pools == null)
+        return;
     pools[pool].update(b);
     if (pool == 0)
       pool0Count++;
@@ -186,6 +168,8 @@ public class FortunaStandalone extends BasePRNGStandalone implements Serializabl
     @Override
   public void addRandomBytes(byte[] buf, int offset, int length)
   {
+    if (pools == null)
+        return;
     pools[pool].update(buf, offset, length);
     if (pool == 0)
       pool0Count += length;

router/java/src/net/i2p/router/RouterContext.java

@@ -170,7 +170,7 @@ public class RouterContext extends I2PAppContext {
             // or about 2 seconds per buffer - so about 200x faster
             // to fill than to drain - so we don't need too many
             long maxMemory = SystemVersion.getMaxMemory();
-            long maxBuffs = (SystemVersion.isAndroid() || SystemVersion.isARM()) ? 3 : 5;
+            long maxBuffs = 3;
             long buffs = Math.min(maxBuffs, Math.max(2, maxMemory / (21 * 1024 * 1024)));
             envProps.setProperty("prng.buffers", Long.toString(buffs));
         }